Control apparatus



' lNov. 3, 1942. I A. w, PLENsLl-:R 2,301,141

CONTROL APPARATUS Filed May 8, 1941 Patented Nov. 3, 1.942

CONTROL APPARATUS Alexander W. Plensler, Chicago,- Ill.,` assignor to Belmont Radio Corporation, a corporation of Illinois 17' claims.

This invention relates in general to control apparatus and more in particular to a mechanical `control device for a tuning system for radio receiving apparatus. A

One form of the mechanical tuning devices of the prior art generally includes a rotatable treadle bar in operative connection with the tuning condensers, a linearly or pivotally movable station selector unit or push button being adapted to rotate the treadle bar to provide for a movement of the condensers to a particular predetermined tuning position corresponding to the station identified by the selector unit. In order that a few push button or selector units can be adapted to tune a large number of predetermined station frequencies, means are provided for making a relative adjustment or setting between the treadle bar and push button in some manner so that each unit may tune more than one station frequency, depending upon the particular setting. This adjustment or setting has been accomplished by some devices in the prior art by an adjustable element in each push button. In these devices, various means have been used to frictionally lock the adjustable element on the push button, but all of these means normally require the use of both hands of the operator during the setting operation so that adjustment is a clumsy and inconvenient operation and sometimes rather difficult.

Many of these prior devices require supplementary tools such as a screw driver or the like :l'or changing the friction pressure on the adjustable element, Particularly in instances, such as little room is provided for both the positioning of the hands and manipulation of the screw driver. Apart from the inconveniences encountered in the adjustment operation, the accuracy of the adjustment is impaired by the tendency of the selector unit to move out of its home positlon while the screw driver is being used so that the adjusted position of the adjustable element is changed before it is locked in a set position.

It is an object of this invention, therefore, to provide an improved control device for control apparat-us and particularly for tunable radio apparatus.

Another object of this invention is to provide control apparatus having a plurality of articulated selector units, each of which has pivoted Application May 8, 1941, Serial No.. 392,475

(Cl. 'I4-10) manipulated for adJusting the unit to a predetermined tuning position.

A further object of this invention is to provide a selector' unit for control apparatus which is simple and rugged in construction, comprised of a small number of stamped out parts, and adapted to be easily andpositively locked in a predetermined tuning position by a simple onehand manipulation vof a pivoted actuating member in an up or down direction. v A feature of this invention is found in the provision of a selector unit of articulated construction having the parts thereof locked in fixed relative positions whenla pivoted actuating portion is in longitudinal alignment with a. body portion of the selector unit, and in which the adjustable element is released for adjustment Iwhen the actuating portion is pivotally moved Further objects, features and advantages of n this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. 1 is a side view of a complete assembly ofthe invention;

Fig. 2 is a sectional View as seen along the line 22 in Fig. 1;

Fig. 3 is illustrated similarly to Fig. 2 showing parts thereof in changed position; and

Fig. 4 is a side view of a modified form of the invention.

In the practice of this invention there is provided a selector unit including a carriage member having a substantially longitudinallyv extending flat portion. An adjustable element is adjustably supported on the body portion and adapted for engagement with; rotary control means when the selector unit is inl its home position. A friction unit for locking the adjustable element in an adjusted position is supported on the carriage member with a portion thereof positioned between the adjustable element and one end of an actuating member, which is pivotally supported at such one end on the carriage member body portion. 'I'he actuating member is adapted to be pivotally moved into longitudinal alignment with the carriage flngerroperated 'means adapted t0 bf? pivotally 55 member body portion, with its movement to such aligned position moving the friction unit to its position for locking the adjustable element. On pivotal movement of the actuating memberout of its aligned position, the friction unit is released to permit free adjustment ofthe adjustable element.

The tuning device of the invention is illustrated in Fig. 1 with representative rotary control means such as a treadle bar I rotatably supported in fixed vframe means II and operatively connected with suitable frequency changing means (not shown). in a manner to rotate the frequency tuning means through an angular distance of 180 to provide for a full range of tuning. The treadle bar I0 is illustrated as being of a substantially V-shaped section, having engaging portions or sides I2 and I2' supported in a. spaced relation by 4an integral slotted portion I3. Rotation of the treadle member I0 to iprovide :for a predetermined frequency tuning position of the frequency changing means is accomplished by means of its operative association with a usual manual control knob, (not shown) and also by actuation of station selector or push button units I4, only one of which is shown.

The push button I4 includes a carriage or operating member I6 and an actuating or lingeroperated member |1 having a knob I8 thereon. 'I'he carriage member is of an irregular shape and formed with an upwardly extending projection I9 and a substantially longitudinally extending fiat portion 2|. The carriage member is pivotally supported for pivotal movement to two operating positions at the projection I9 on a pin or axis means 22 mounted in the side walls (not shown) of the frame means II, the pin 22 being inserted through a corresponding aperture formed in the projection I9. As shown in Fig. l, the carriage member, and hence the selector unit, is in its Vrest or idle position, which is denned by the engagement of the iiat side 23 of the carriage member with a front wall 24 of the frame means II. Movement of the selector unit to this rest position is accomplished by a spring 26 which is connected at one end to the carriage member and at its opposite end to a'. portion of the frame means I I.

An adjustable cam or driving element 21 of substantially semi-circular shape is rotatably supported by a pin 28 or the like near one end of the c-arriage body portion 2 I, with its flat portions 26 and 29 facing normally in the direction of the treadle bar IIJ for engagement with the portions I2 and I2', respectively, Axis means 30 in alignment with the pivot 28 longitudinally of the carriage body portion 2| pivotally supports the actuating member I1 at its end 3| on the carri-age portion. 'I'he end 3| of the actuating member is of substantially accurate contour and is formed with a iiat portion thereon to provide a cam 32 at such end for a purpose to be later explained. A friction or spring unit4 33 for lock- -ing the element 21 in an adjusted position is supported near its upper end on the carriage niember on a pivot 34, with its opposite end 36 positioned intermediate the adjustable cam 21 and the end 3| of the actuating member I1. The

end 36 of the spring unit 33 is substantially at with its side adjacent the adjustable element 21 having -a contour-adapted for mating engagement with the circular contour of the element 21. 'I'he other side of the spring end 36 is of straight form and engageable with the cam 32 at the end 3| of the actuating member I 1. It is seen, therefore, that the movement of the spring end 36 longitudinally of the carriage portion 2| is lin..- ited in one direction by a xed stop provided by the cam element 21 and in an opposite direction by an adjustable stop provided by the cam 32 at the end 3| of the actuating member I1.

As previously mentioned the spring end 36 is of substantially fiat form. In practice it is contemplated that the distance between the arcuate edge of the adjustable element 21 and the edge of the cam 32 for one operating position of the actuating member be such that the spring end 36 is longitudinallyfreely expansible therebetween to permit a substantially free movement of the element 21 about its pivot 28. This nonholding or non-friction applying position of theV spring unit is illustrated in Fig. 3 and occurs when the actuating member I1 is in the position shown by dotted lines in Fig. l. On pivotal movement of the actuating member to its fullline position shown in Fig. 1, the high portion of the cam 32 is rotated against the spring end 36, which is contracted between the cam and the element 21 in a manner to apply a frictional holding pressure on the element sufcient to positively lock it in an adjusted position. It is to be' understood, of course, that the spring end 36 need only be assembled relative to the adjustable element 21 and the cam portion 32 such that the spring in its released position may expand sufficiently to reduce the frictional pressure applied on the cam element 21 and to permit a free rotation thereof. Since only a slight contraction of the spring end 36 is necessary to effect a large frictional pressure on the adjustable element 21 it is apparent, therefore, that but' a very small rise in the cam portion 32 and a correspondingly small pivotal movement of the actuating member I 1 is required to securely lock the element 21 in an adjusted position.

'Ihe Spring unit when in its element holding position is bowed laterally outwardly from the carriage portion 2|, as is clearly shown in Fig. 2, the spring pressure resulting fro-m the spring 'contraction provided by the cam 32 and the extensive bearing surface between the spring and element 21, positively locking the element 21, the spring 33 and the actuating member I1 in fixed positions relative to the carriage number I6. Since the spring end 36 is of a smaller thickness than the element 21 and actuating member I1, a spacing or rest block 25 bumped out from the carriagel portion 2| intermediate the element 21 and cam 32 is provided to retain the spring end away from the carriage portion and in an engagingposition relative to such two defined parts, Wedging of the spring end between one of such two parts and the carriage member is thus entirelyeliminated so that a positive action of the spring. for locking the element 21 is provided whenever the cam 32 is moved into frictional engagement therewith.

As shown in Fig. 1 the actuating member I1, when the unit 33 is in its pressure applying or Aholding position, is extended longitudinally of the carriage portion 2|. The unit I4 is thus seen to be of articulated construction, with the actuating member being pivotally movable out of longitudinal alignment with the carriage portion 2| to release the spring 33 from its element locking position, and into longitudinal alignment therewith to move the spring into its locking position. Pivotal movement of the actuating member to its operating positions is defined by lugs or stops 31 and 31 punched out on the carnage member I6. When the actuating member,l

position, as shown in Fig. 1, the knob I8 on thel actuating member is manually gripped and pulled upwardly to pivotally move the actuating member from its position against the lug 31 to its dotted line position against the lug 31. By virtue pivot 22 and the engagement of the carriage member side portion 23 against the frame wall 24, the rest position of the selector unit I4 is positively vretained during this pivotal movement of the actuating member I1, so that the release of the spring unit 33 from a holding to a nonvholding position relative to the adjustable element 21 is simply accomplished by a one-hand manipulation of the actuating member.

. Withthe actuating member in its dotted linek position the selector unit I4 isl pivotally moved `inwardly towardthe treadle bar I0, the portions '29 and 2B on the adjustable element 21 moving c into engagement withthe corresponding portions therefore, is in an operating position extended frame element 4| and the body portion 38, is a spring 42 adapted to retain the selector unit I4' in its idle or rest position, this position being defined by the engagement of a shoulder portion v43 on the carriage member with the front wall 24' of the frame means II.- The element 21, a spring unit 33', and an actuating member I1 are substantially similar in all respects to the correspondingl p parts in Fig. l, so that a further description of of the pivotal support of the selector unit on the the construction of and relative assembly of these `parts is believed to be unnecessary.

In the adjustment of the selector unit I4' to a setting corresponding to a predetermined control position of the treadle bar I0, the actuating member I1' is pivotally moved upwardly from its full-line position to its dotted-line position,

asshown in Fig. 4, to release the spring unit 33 from its element locking position. With the actuating member I1 in its dotted-line position, the selector unit I4' is linearly moved into engagement with the treadle bar I0 to rotate the adjustable cam element 21 to a position corre` sponding to the predetermined control position of the treadle bar.L It is to be understood, of

course, that the element 21 is freely rotatable y ,about its pivot 28 by-virtue of the release of the spring unit 33 from' its friction applying posi- I2 and I2' on the treadle bar I0, because of the element 21 being freely rotatable on the pivot 28.; While the element 21 is engaged with the ltreadle bar IIJ the actuating member I1 is pivotally moved downwardly from its dotted line position to its full-'line position against the lug 31' whereby to move the spring 33 to its friction applying position forlocking the element 21 in such adjustedposition in the manner above fully described. Because ofy the pivotal support of the selector unit I4 at thelpivot 22 and the engagement of'the cam 21 against the .treadle bar I0,

. the unit I4 is retained stationary in itshome position while the actuatingrnember I1 is pivotally manipulated. It is seen, therefore, that both the release and the lockingof the element 21 is simply accomplished merely by pivotally movingwith one hand the actuating or-ilnger operated member I1.

On locking of the element 21 in its adjusted position ythe actuating member I1 is released and the selectorunit `I4 is returned to its rest posi- `tion by the action of the spring 26. With all of the parts of the selector unit locked in iixed relative positions. it is apparent of course that later actuation of the selector unit to its home position operates to rotate the treadle bar IU to the control position for vwhich the selector unit has been set. It is contemplated that the axis of the treadle bar I0 be positioned in the arcuate path taken by the elementaxis means 28 on pivotal movement of the selector unit I4 to provide for an increased accuracy in the element setting.

e In the modiiled form of the invention shown in Fig. 4, the carriage'unit I6 is provided with a flat body portion 38 having the adjustable element 21 at one end thereof, the opposite end of the Abody portion being slidably supported in a ,ly on the nger knob I8'.

tiononmovemlent of the actuating member to its dotted line position against the stop 31. After the element 21 has been thus rotated to its adjusted position the actuating membery I1' is moved pivotally downward against the stop 31 to lock the element in such adjusted position; On release of the actuating member I1' the unit I4' is returned to its rest position by the action of the spring 42. Because of the slidable support of the carriagemember I6. in the front wall 24 'and 'in the frame element 4I, the .selector unit I4 is positively retained in each of its home and rest positionsduring the manipula-tionv of the actuating member I1', so that setting of the selector unit I4 is simplv accomplished by a onc- `hand manipulation ofthe actuating member I1.'

I'he lug 31 Vdefines a position ofthe actuating member I1 in longitudinal alignment with'the body portion 38 so that the selectorunit I4 is in substantial alignment longitudinally when it is actuated in normal operation by pushing inward- From the above description and consideration of the drawing, it is seen that the invention provides control apparatus which can be readily adjusted to various predetermined positions for accomplishing tuning at those positions; In both of the illustrated embodiments the adjustable element is releasablyl locked in a set position by `friction means including a member having a portion thereofin a plane substantially parallel to the plane of the 'carriage memberand parallel or coplanar with the plane of the adjustable element. The frictional forces are applied and removed simply and with one hand by merely pivotally moving in an up-and-down direction a finger operated member. Particularly in the case of small or portable receiving sets, it is apparent that' this direction of movement of the ngeroperated member and the adjustment of the selector unit, practically eliminates any movement of the receiving set during the adjusting operation because of the application of the locking and releasing forces in a substantially vertical direction.

Although the invention has been specifically described with reference to two embodiments thereof, it is to be understood that it is not to be so limited, since modifications and alterations in the parts and their arrangement can be made therein which are within the intended scope of this invention as defined by the appended claims.

I claim: L. l. In control apparatus having rotary control means, the means for rotating said rotary control means to predetermined control positions includ- 1 ing a movable carriage unit having an adjustable element pivotally supported thereon, an actuator unit pivotally supported at one end on said carriage unit, with said one end having a cam portion thereon, friction means for locking said adjustable element in an' adjusted position., and means supporting said friction means on said carriage unit intermediate said adjustable element and said cam portion, said cam portion on pivotal movement of said actuator unit in one direction moving said friction means to apply a frictional pressure on said adjustable element to lock they same in an adjusted position.

2. In control apparatus having movable control means, the means for moving said movable control means including an articulated selector unit having a movably supported body portion and a finger-operated portion, means pivotally supporting said nger operated portion at one end on said body portion, an adjustable element adjustably supported on said body portion, friction means for locking said adjustable element in an adjusted position, means supporting said friction means on said body portion .intermediate said adjustable element and finger-operated portion, said adjustable element defining the movement of said friction means in one direction, and the one end of said finger operated ,portion delining movement of said friction means in an opposite direction, said one end having a cam surface thereon operatively engageable with said friction means, with pivotal movement of said finger-operated portion in one direction engaging said cam surface and friction means to move said friction means to a position for applying a frictional locking pressure on said adjustable element.

3. In control apparatus having movable control means, the means for moving said control means to predetermined control positions includi ing a carriage unit, means movably supporting said carriage unit for movement to two operating positions, finger-operated means pivotally supported at one end on said carriage unit, said one end having a cam portion thereon, an adjustable element adjustably supported on said carriage unit, and a flat spring member supported on said carriage unit intermediate said adjustable element and the one end of said finger-operated means, with one portion of said at spring being frictionally engageable with said adjustable element and an opposite portion thereof being engageable with said cam portion, said cam portion on pivotal movement of said finger-operated means in one direction, when said carriage unit is in one of said operating positions, urging said flat spring into frictional engagement with said adjustable element to lock the same in an adjusted position.

4. In control apparatus having movable lcontrol means, an articulated selector unit for moving said control means having a body portion and a nger operated portion, means pivotally supporting said finger-operated portion at one end on said body portion, said one end having a cam surface thereon, an adjustable element adoperatively engageable with said movable control means, means movably supporting said body portion formovement to two operating positions, means for applying a frictional pressure on said adjustable element to lock the -same in an adjusted position, and means supporting said locking means on said body portion intermediate said adjustable element and the end of said ngeroperated portion, said cam surface on pivotal movement of said finger-operated portion when said body portion is in vone of said operating positions engaging said locking means to apply a frictional locking -pressure on said adjustable element, said finger-operated means being pivotally movable in an opposite direction when the body portion is in the vother of said operating positions to provide for the release of said locking pressure on said adjustable element.

5. In control apparatus having movable control means, the means for moving said control means including a supporting unit and an actuating member, means pivotally connecting said actuating member at one end with said supporting unit for movement to two operating positions, said one end having a cam portion thereon, an adjustable element adjustably supported on said supporting unit, a substantially iiat spring unitv unit and in a position intermediate-said adjusti able element and said cam portion, said spring unit when said'actuating member is in one of said operating positions being in a non-holding position relative to said adjustable element, with pivotal movement of said actuating member to the other of its operating positions engaging said cam portion and said spring unit to urge the same into a frictional holding position relative to said adjustable element.

6. In control apparatus having movable control means, the means for moving said control means including a carriage unit` and nger operated means, means movably supporting said carri-age unit for movement to two operating positions, with a longitudinal portion of said carriage unit being movable in a substantially linear direction, means pivotally supporting said finger operated means at one end on said carriage unit, with said one end having a cam portion thereon, an adjustable element adjustably supported on said longitudinal portion, means for applying a friction-al holding force on said adjustable element to lock lthe same in an adjusted position, means supporting said locking means on said carriage unit intermediate said adjustable element and cam portion, said locking means being urged into a friction applying position by said cam portion when said finger operated means is in substantial longitudinal alignment with said carriage portion, and said adjustable element being adjustable when said nger operated means and carri-age portion are out of 1ongitudinal alignment, said carriage unit when said adjustable element is in an adjustable position being movable to one of said operating positions by said finger operated means, with said element being locked in an adjusted position at said one operating position on pivotal movement of the finger operated means into longitudinal alignment with said carriage portion, said nger operated means when said carriage unit is justably .supported on said body portion and in the other of said operating positions being piv.

, .2,801,141 .otally movable to release the holding pressure on said adjustable element, and means retaining said carriage unit stationary in said operating positions on manipulation of said finger operated means to frictionally lock and release said adjustable element.

7. In control apparatus having movable control means, the means for moving said control` ing a carriage unithaving a substantially nat means including a carriage unit and iinger-operated means, means supporting said carriage unit for movement to two operating positions,v

said carriage unit having a substantially linearly movable longitudinal portion, axis means pivotally supporting said linger-operated means at one end on said carriage unit, said one end hav- `adjustable element to lock the same in an adjusted position, means supporting said friction means on said carriage unit in a position intermediate said adjustable element and cam portion, said finger-operated means being in lon-- gitudinal alignment with said carriage unit portion to normally engage said cam portion and friction means for applying a frictional-holding pressure on said adjustable-element, said linger; operated means when said carriage .unit is in one of said operating positions being pullable upwalrdly out of longitudinal alignment with said carriage unit vportion to release said friction means from a friction-applying position,

said carriage unit with said finger-operated means in said upward position being movable to the other of said operating positionspwith said linger-operated means being pushable downwardly when said carriage is in said other operating position to move said friction means into friction applying position, 'and means support'- ing said carriagel vunit on at least two points when-it is in each of said operating positions to retain the carriage unit stationary during the manipulation of said iinger-operated means.

8. In control apparatus having movable control means, the means for moving said control Y means to predetermined control positions includ-v ing a carriage member having a substantially ilat longitudinally extending bodyportion, an adjustable element adjustably. supported on said body portion, an actuating member pivotally connected at one end to Asaid carriage member, said one end having a cam portion thereon, a substantially iiat spring unit supported on said body portion and adapted to frictionally hold said adjustable element in an adjusted position, with a portion of said spring unit being positioned intermediate said adjustable element and said cam portion, said adjustable element, spring portion, and cam portion lyingl in a plane substantially parallel to the plane of said carriage member body portion, and means on said body portion supporting said spring portion laterally therefrom, said cam portion on pivotal movement of said actuating member to a position in longitudinal alignment with said carriage member body portion engaging and bowing said spring unit to apply a frictional holding pressure on said adjustable element.

means to predetermined control positions includ- 75 longitudinally extending body portion, finger-operated means pivotally supported at one end on said body portion tor pivotal movement to a position in longitudinal alignment therewith, said one end having a cam portion thereon, an

adjustable element adjustably supported on said body portion, a substantially nat spring unit for applying a frictional holding pressure on said adjustable. element to lock the same in an adjusted position, means supporting said spring atJone end on said body portion, with its opposite end positionedA substantially intermediate said adjustable element and cam portion, said spring unit being in a plane substantially parallel to the plane of said body portion when in a non-friction applying position, and said cam portion on pivotal movement of said ngeroperated means to said longitudinally .aligned` position engaging and moving said `opposite spring end into frictionalI engagementwith said adjustable element, with said spring unit in its element` holding position being laterally bowed relative to the plane of said body portion.

10. In control apparatus having movable cron-` trol means, the means for moving` said control `means topredetermined control positions including a supporting memberhaving a at body portion, an adjustable element, axis means rotatably supporting said adjustable element on saidbody portion, iinger-operated means, second axis meansv pivotally supporting said finger-operated meansat one end on said bodyy portion,` said twov axis means being in alignment longitudinally of said body portion, a springunit adapted to apply a frictional holding pressure on said'adj'ustable element `to lock the sainev in an adjusted-position,

and means'supporting said. spring unit at one end on said carriage unit, with its'opposite end positionedV intermediate said two axis means, with movement of said opposite spring end being confined longitudinally of said bodyportion by said adjustable element and the oneend of said fingeroperated`means,said oneV end having a contour suchl that on pivotal movement of said iinger-operated means in .one direction ysaid spring -unitA is urged thereby' into frictional engagement with said. adjustable element, with said finger-operated means on; pivotal movement` thereof in anv oppositeV direction releasingsaid spring unit to permit adjustment of said-'adjustl able element. i

1l. In control apparatus havingmovablecontrol means, the means. for movingsaid control means including an operating unit and vari'actuating unit, means pivotallysupporting said operating unit forv pivotal movement to `two operating positions, said operating unit having a flat longitudinally extending portion.`movable in a' substantially linear direction between said two operating positions, an adjustable element adjustably Supported on said at portion, means pivotally supporting said actuating unit at one end on said iiatv portion, said one end having a cam portion thereon, a` friction element for applying a frictional holding force on said adjustable element to lock the same in an adjusted position, means supporting said friction unit on said operating unit intermediate said adjustable element and said cam portion, said friction element having onesiae engageame with said ad justable element andan opposite side engageable Vwith said cam portion, said actuating unit'on pivotal movement thereof in one direction transversely of said ilat portion when said operating` unit is 'in one of saidioperating positions moving said cam .portion to permit relative movement between said adjustable element and the one side of said friction element, with pivotal movement of said actuating unit in an opposite direction into longitudinal alignment with said at portion when said operating unit is in the other of its operating positions movingsaid cam portion into engagement with the opposite side of said friction element to frictionally engage the one side of said friction element with said adjustablevelem'ent, means defining the two operating positions of said carriage unit, and stop means on said carriage unit for limiting the pivotal movement of said actuating unit.

12. In control apparatus having movable control means, the means for moving said control means including a carriage unit having an adjustable element ladjustably supported thereon, means slidably supporting said carriage unit for longitudinal movement to' two operating positions, a nger-operated unit, means pivotally supporting said iinger-operated unit at one end on said carriage unit for pivotal movement transversely of said carriage unit, said one end ment with said carriage unit, when the carriage unit is in one of said operating positions, bending said spring member against said adjustable element to apply a frictional locking pressure on said element, with said cam portion on pivotal movement of said finger-operated unit out of said aligned position when said carriage unit is in the other of said operating positions releasing said spring member until it is of substantially straight line contour to permit relative movement between said spring member and said adjustable member, and means on said carriage unit for limiting the pivotal movement of said finger-operated unit.

13. In a control unit having a body portion with adjustable means thereon, an actuating member pivoted on said body portion, resilient locking means operatively connected with said adjustable means and actuating member, and means mounting said resilient means on said body portion, said actuating member on pivotal movement to one operating position therefor acting on said resilient means to produce a fricticnal pressure therein for application on said adjustable means .and actuating member, said frictional pressure locking said adjustable means in an adjusted position and releasably retaining said actuating member in said one operating position.

14. In a control unit having a body portion with pivoted adjustable means thereon, a pivoted jnger-operated member supported on said body portion, and resilient means operatively connected with said adjustable means supported on said body portion, said linger member having ing said adjustable means in 'an adjusted position and releasably retaining said finger member in said one operating position, said engaging portion on pivotal movement of said finger member in a reversedv direction releasing saidresilient means to permit a free pivotal movement of said adjustable means.

15,. In a control unit having a body portion and pivoted adjustable means thereon, a pivoted finger-operated portion supported on said body portion and pivotally movable to a rest and an operating position, means for locking said adjustable means in an adjusted position concurrently with the pivotal movement of said nger portion from said rest to said operating position including resilient means supported on said body portion .operatively connected with said adjustable means and nger portion, said iinger portion on pivotal movement thereof to said operating position acting on said resilient means to produce a pressure therein for application on said finger portion and adjustable means, said pressure locking said adjustable means in an adjusted position and releasably retaining said finger portion in said operating position, with pivotal movement of said nger portion to said rest position releasing said pressure to provide for the free pivotal movement of said adjustable means.

16. In a control unit having a body portion with, adjustable means thereon, a pivoted ngeroperated portion supported on said body portion, pivotally movable to one position to release said adjustable means and to a second position to lock the adjusted means in an adjusted position, and means operatively connecting said adjustable means and finger-operated portion including resilient means supported on said body portion, said linger portion on pivotal movement thereof from said one to said second position acting on said resilient means to deform the same and produce a pressure therein for application on said iinger portion and adjustable means. said pressure providing for the frictional locking of said adjustable means in an adjusted position Aand the frictional holding of said finger portion adapted to be deformed by said engaging portion g to apply a frictional pressure against said adjustable means and nger member, said frictional pressure locking said adjustable means in an adjusted position and releasably holding said iinger portion in a position to retain the resilient means deformed.

W. PLENSLER. 

